Light source device and display device

Abstract

To provide a light source device and a display device capable of suppressing leakage of light not only in a space between a substrate and an incident surface of a diffusion plate but also in a space on a side opposite to a plurality of light sources with respect to an emission surface of the diffusion plate.SOLUTION: The light source device 40 includes the plurality of light sources 2 and the diffuser 4 that is disposed so as to face the plurality of light sources 2 and diffuses light emitted from the plurality of light sources 2. The light source device 40 includes an incident surface-side light-shielding wall 3 that surrounds each of the plurality of light sources 2, is provided so as to partition each region Ar corresponding to each of the plurality of light sources 2, and extends from a light incident surface 41 of the diffuser plate 4 toward the plurality of light sources 2, and an emission surface-side light-shielding wall 5 that partitions each region Ar corresponding to each of the plurality of light sources 2, and extends from a light emission surface 42 of the diffuser plate 4 toward a side opposite to the plurality of light sources 2.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a light source device and a display device, and more particularly to a light source device and a display device that include a diffusion plate. [Background technology]

[0002] BACKGROUND ART Conventionally, a light source device equipped with a diffusion plate is known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 describes a light-emitting device equipped with a diffuser plate. This light-emitting device includes a plurality of light sources, a substrate, and a partitioning member. The plurality of light sources are arranged on the substrate. The diffuser plate is arranged above the light sources. The partitioning member is configured to surround each of the plurality of light sources, thereby partitioning the areas of each of the plurality of light sources. The partitioning member is arranged between the substrate and the incident surface of the diffuser plate. This prevents light from one of the adjacent light sources from propagating through the space between the substrate and the incident surface of the diffuser plate and leaking into the area where the other light source is arranged. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-82802 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the light source device described in Patent Document 1, the partition member is disposed only between the substrate and the incident surface of the diffuser plate. Therefore, light from one light source emitted from the exit surface of the diffuser plate leaks into the area of ​​the other light source in the space on the opposite side of the diffuser plate from the multiple light sources. This causes light to be emitted from the display panel at an unintended viewing angle. Therefore, it is desirable to suppress light leakage not only in the space between the substrate and the incident surface of the diffuser plate, but also in the space on the opposite side of the diffuser plate from the multiple light sources.

[0006] This invention has been made to solve the above-mentioned problems, and one object of this invention is to provide a light source device and a display device that can suppress light leakage not only in the space between the substrate and the incident surface of the diffuser plate, but also in the space on the opposite side of the exit surface of the diffuser plate from the multiple light sources. [Means for solving the problem]

[0007] A light source device according to a first aspect of the present invention includes a plurality of light sources, a diffuser plate arranged opposite the plurality of light sources and diffusing light emitted from the plurality of light sources, an incident surface side shading wall surrounding each of the plurality of light sources and arranged to partition the area into regions corresponding to each of the plurality of light sources and extending from the light source side toward the light incident surface side of the diffuser plate, and an exit surface side shading wall arranged to partition the area into regions corresponding to each of the plurality of light sources and extending from the light exit surface of the diffuser plate toward the opposite side to the plurality of light sources.

[0008] As described above, the light source device according to the first aspect of the present invention includes an incident surface-side light-shielding wall and an exit surface-side light-shielding wall. The incident surface-side light-shielding wall can thereby suppress leakage of light from each of the multiple light sources into adjacent spaces between the substrate and the incident surface of the diffuser. The exit surface-side light-shielding wall can also suppress leakage of light from each of the multiple light sources into adjacent spaces on the opposite side of the exit surface of the diffuser from the multiple light sources. This suppresses light leakage not only in the space between the substrate and the incident surface of the diffuser, but also in the space on the opposite side of the exit surface of the diffuser from the multiple light sources. Furthermore, suppressing light leakage can suppress light from emitting at unintended viewing angles from the display panel in the regions of each of the multiple light sources.

[0009] In the light source device according to the first aspect, the light-emitting surface-side shielding wall preferably includes an light-emitting surface-side insertion portion inserted from the light-emitting surface of the diffuser plate toward the light-incident surface. With this configuration, the light-emitting surface-side insertion portion can block (absorb or reflect) light that propagates through the diffuser plate toward the area where the other light source is located and that has penetrated to the light-emitting surface side of the diffuser plate. This can prevent light from one of the adjacent light sources from leaking into the area where the other light source is located. As a result, it can prevent light from leaking from one of the light sources (unwanted light) from emitting at an unintended viewing angle from the display panel.

[0010] In this case, the diffuser plate preferably includes an exit surface groove recessed from the exit surface toward the incident surface, into which the exit surface insertion portion is inserted. With this configuration, by inserting the exit surface insertion portion into the exit surface groove, the light emitted from the exit surface groove can be blocked by the exit surface insertion portion, thereby further preventing light from one adjacent light source from leaking into the area where the other light source is arranged.

[0011] In the light source device according to the first aspect, the incident surface-side light-shielding wall preferably includes an incident surface-side insertion portion inserted from the incident surface of the diffuser plate toward the exit surface. With this configuration, the incident surface-side insertion portion can block (absorb or reflect) light on the incident surface side of the diffuser plate that propagates through the diffuser plate toward the area where the other light source is located. This can prevent light from one of the adjacent light sources from leaking into the area where the other light source is located. As a result, it can prevent light from leaking from one of the light sources (unwanted light) from emitting at an unintended viewing angle from the display panel.

[0012] In this case, the diffuser plate preferably includes an incident surface groove recessed from the incident surface toward the exit surface, into which the incident surface insertion portion is inserted. With this configuration, by inserting the incident surface insertion portion into the incident surface groove, the incident surface insertion portion can easily block the light emitted from the incident surface groove, thereby further preventing light from one adjacent light source from leaking into the area where the other light source is arranged.

[0013] In the light source device according to the first aspect, preferably, the portion of the incident surface-side light-shielding wall on the exit surface side is disposed in a portion of the interior of the diffuser plate from the incident surface of the diffuser plate toward the exit surface side, and the portion of the exit surface-side light-shielding wall on the incident surface side is disposed in a portion of the interior of the diffuser plate from the exit surface of the diffuser plate toward the incident surface side. With this configuration, for light propagating through the diffuser plate toward the area where the other light source is disposed, the portion of the incident surface-side light-shielding wall disposed in a portion of the interior of the diffuser plate can block (absorb or reflect) the light on the incident surface side of the diffuser plate, and the portion of the exit surface-side light-shielding wall disposed in a portion of the interior of the diffuser plate can block (absorb or reflect) the light on the exit surface side of the diffuser plate. This effectively prevents light from one of the adjacent light sources from propagating through the diffuser plate and leaking into the area where the other light source is disposed.

[0014] In this case, the diffuser preferably includes a portion of the incident-side light-shielding wall on the exit surface side and a portion of the incident-side light-shielding wall on the entrance surface side, each disposed within the diffuser, and includes a plurality of grooves arranged offset in a direction perpendicular to the direction from the incident surface toward the exit surface (e.g., vertical, a direction intersecting the vertical, or horizontal), and a serpentine-shaped portion along the incident and exit surfaces of the diffuser, the grooves causing the light to bend back in both the direction from the incident surface toward the exit surface and the direction from the exit surface toward the incident surface. With this configuration, light from one light source does not propagate through the diffuser in a direction parallel to the direction from one light source to the other light source, but the serpentine-shaped portion changes the propagation direction of the light in various directions, making it difficult for the light from one light source to propagate through the diffuser and reach the area where the other light source is located. Furthermore, the serpentine-shaped portion can extend the optical path length of light propagating through the diffuser in the direction from one light source to the other light source, thereby increasing the number of reflections and diffusions of the propagating light. This makes it possible to further reduce the amount of propagating light, thereby further suppressing light leakage from one light source to an adjacent region of the other light source.

[0015] A light source device according to a second aspect of the present invention comprises a plurality of light sources, a diffuser plate arranged opposite the plurality of light sources and diffusing light irradiated from the plurality of light sources, an exit surface side shading wall arranged on the side of the diffuser opposite the plurality of light sources and dividing the diffuser plate into regions corresponding to the plurality of light sources, and an incident surface side shading wall arranged on the side of the plurality of light sources of the diffuser plate and surrounding the plurality of light sources in each region corresponding to the plurality of light sources, wherein the exit surface side shading wall is arranged inside the diffuser plate from the outer surface of the diffuser plate opposite the plurality of light sources toward the plurality of light sources, and the incident surface side shading wall is arranged inside the diffuser plate from the outer surface of the diffuser plate on the side of the plurality of light sources toward the opposite side to the plurality of light sources.

[0016] In a light source device according to a second aspect of the present invention, as described above, an exit surface-side light-shielding wall and an incident surface-side light-shielding wall are provided. The incident surface-side light-shielding wall can thereby suppress leakage of light from each of the multiple light sources into adjacent spaces between the substrate and the incident surface of the diffuser. The exit surface-side light-shielding wall can also suppress leakage of light from each of the multiple light sources into adjacent spaces on the opposite side of the exit surface of the diffuser from the multiple light sources. This suppresses light leakage not only in the space between the substrate and the incident surface of the diffuser, but also in the space on the opposite side of the exit surface of the diffuser from the multiple light sources. Furthermore, suppressing light leakage can suppress light from emitting at unintended viewing angles from the display panel in the regions of each of the multiple light sources.

[0017] As described above, the display device according to the third aspect of the present invention includes a plurality of light sources, a diffusion plate arranged opposite the plurality of light sources and diffusing light irradiated from the plurality of light sources, a display panel arranged on the opposite side of the diffusion plate from the plurality of light sources, an incident surface side light-shielding wall surrounding each of the plurality of light sources and arranged to partition the display panel into areas corresponding to each of the plurality of light sources and extending from the light source side toward the light incident surface side of the diffusion plate, and an exit surface side light-shielding wall arranged to partition the display panel into areas corresponding to the plurality of light sources and extending from the light exit surface of the diffusion plate toward the opposite side to the plurality of light sources.

[0018] A display device according to a third aspect of the present invention includes an incident surface-side light-shielding wall and an exit surface-side light-shielding wall, as described above. The incident surface-side light-shielding wall can thereby suppress leakage of light from each of the multiple light sources into adjacent spaces between the substrate and the incident surface of the diffuser. The exit surface-side light-shielding wall can also suppress leakage of light from each of the multiple light sources into adjacent spaces on the opposite side of the exit surface of the diffuser from the multiple light sources. This makes it possible to provide a display device that can suppress light leakage not only in the space between the substrate and the incident surface of the diffuser, but also in the space on the opposite side of the exit surface of the diffuser from the multiple light sources. [Effects of the Invention]

[0019] According to the present invention, as described above, it is possible to suppress light leakage not only in the space between the substrate and the incident surface of the diffuser plate, but also in the space on the opposite side of the exit surface of the diffuser plate from the multiple light sources. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a perspective view showing the overall configuration of a display device according to an embodiment of the present invention; [Figure 2] 1 is an exploded perspective view of a display device according to an embodiment of the present invention; [Figure 3] FIG. 2 is an enlarged cross-sectional view of a backlight according to an embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 2 is an enlarged cross-sectional view of a meandering portion of a backlight according to an embodiment of the present invention. [Figure 6] FIG. 2 is a partial perspective cross-sectional view of a serpentine-shaped portion of a backlight according to an embodiment of the present invention. [Figure 7] FIG. 10 is an enlarged cross-sectional view of a backlight according to a modified example of one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings.

[0022] (Display device configuration) The configuration of a display device 100 according to one embodiment of the present invention will be described with reference to FIGS.

[0023] 1, the display device 100 is, for example, a liquid crystal television device. The display device 100 performs local dimming control to adjust the brightness for each of a plurality of areas Ar (see FIG. 3) partitioned on the screen.

[0024] In the drawings, the left-right direction when viewing the display device 100 from the front side is indicated as the X direction, the up-down direction when viewing the display device 100 from the front side is indicated as the Y direction, and the direction connecting the rear side and front side of the display device 100 is indicated as the Z direction.

[0025] As shown in Fig. 2, the display device 100 includes a front housing 10, a display panel 20, an intermediate frame 30, a backlight 40, a rear housing 50, and a control unit 60 (see Fig. 1). The display panel 20, the intermediate frame 30, and the backlight 40 form a display unit. The backlight 40 is an example of a "light source device" in the claims.

[0026] The front housing 10 is made of, for example, resin. The front housing 10 is configured to support the display panel 20 from the front side (Z1 direction side). A rectangular opening is provided in the center of the front housing 10 to expose the display surface of the display panel 20 to the front side (Z1 direction side).

[0027] The display panel 20 includes a liquid crystal cell. The display panel 20 also includes a plurality of pixels, each of which changes the transmittance of light emitted from the light source 2 to display an image. The display panel 20 is driven based on a video signal.

[0028] The intermediate frame 30 is configured to support the display panel 20 from the lateral sides (X1 direction sides and X2 direction sides) and from the top and bottom directions (Y1 direction sides and Y2 direction sides).

[0029] The backlight 40 is disposed on the rear side (Z2 direction side) of the display panel 20. The backlight 40 is configured to irradiate the display panel 20 with light from the rear side toward the front side (Z1 direction side) of the display panel 20.

[0030] The rear housing 50 is configured to support the display panel 20 from the rear side (Z2 direction side). The rear housing 50 is formed, for example, from metal, and is formed in a concave shape recessed toward the rear side (Z2 direction). The rear housing 50 is combined with the front housing 10.

[0031] The front housing 10 and the rear housing 50 form a housing.

[0032] 1, the control unit 60 is configured to control the display device 100. The control unit 60 includes a CPU (Central Processing Unit) and a storage unit such as a memory. The control unit 60 also performs local dimming control to adjust the brightness of each of a plurality of regions partitioned on the screen of the display panel 20.

[0033] (Backlight configuration) As shown in FIG. 2, the backlight 40 includes a substrate 1, a plurality of light sources 2, an incident surface side light-shielding wall 3, a diffusion plate 4, an exit surface side light-shielding wall 5, and a lens unit 6.

[0034] In the backlight 40, facing the display panel 20, a substrate 1, an incident surface side light-shielding wall 3, a diffusion plate 4, an exit surface side light-shielding wall 5, and a lens section 6 are stacked and arranged in this order.

[0035] In the backlight 40, light from the plurality of light sources 2 on the substrate 1 arranged on the Z2 side is irradiated toward the display panel 20 arranged on the Z1 side. The light from the plurality of light sources 2 is reflected (blocked) by the incident surface-side light-shielding wall 3 toward the diffuser plate 4. The light directed toward the diffuser plate 4 by the incident surface-side light-shielding wall 3 is diffused by the diffuser plate 4. Then, of the light diffused by the diffuser plate 4, the light other than that absorbed (blocked) by the exit surface-side light-shielding wall 5 is directed toward the lens unit 6. This light directed toward the lens unit 6 is incident on the lens unit 6. The light incident on the lens unit 6 is refracted by the lens unit 6 and irradiated as parallel light toward the display panel 20. That is, after being diffused by the diffuser plate 4, the light from the plurality of light sources 2 is irradiated toward the display panel 20 arranged on the opposite side (Z1 side) of the diffuser plate 4 from the plurality of light sources 2. In this manner, light is irradiated toward the display panel 20 for each of the plurality of regions Ar (see FIG. 3) partitioned on the screen of the display device 100.

[0036] (substrate and light source) The substrate 1 is, for example, a printed circuit board. The substrate 1 is provided with a circuit to which the plurality of light sources 2 are electrically connected. The substrate 1 is also provided with a control unit 60. The control unit 60 may be provided separately from the substrate 1.

[0037] The plurality of light sources 2 include, for example, light-emitting elements. The light sources 2 are configured to emit light when energized. The light sources 2 include, for example, LEDs (Light Emitting Diodes). The light sources 2 are attached to the rear housing 50 via a substrate 1. The plurality of light sources 2 are arranged in a matrix, with multiple light sources 2 aligned in each of the X and Y directions. The brightness of each of the plurality of light sources 2 is individually adjusted by the current value under the control of the control unit 60. Note that, for example, several tens to several hundreds of light sources 2 are arranged in a row.

[0038] (Incidence side light shielding wall) The incident surface-side light-shielding wall 3 surrounds each of the multiple light sources 2 in each region Ar (see FIG. 3) corresponding to the multiple light sources 2. The incident surface-side light-shielding wall 3 extends from the multiple light sources 2 side toward the light incident surface 41 side (Z1 direction side) of the diffuser 4. The incident surface-side light-shielding wall 3 is arranged to surround each light source 2 across the region Ar from the surface of the substrate 1 on the Z1 direction side to the incident surface 41 on the light source 2 side (Z2 direction side) of the diffuser 4. The incident surface-side light-shielding wall 3 is formed from, for example, resin. Here, the regions corresponding to the multiple light sources 2 are regions corresponding to each of the multiple convex lenses of the lens unit 6 when viewed from the Z1 direction side.

[0039] The incident surface side light-shielding wall 3 is configured to reflect light from the light source 2 on the outer surface of the incident surface side light-shielding wall 3. As a result, the light is reflected and light directed toward the area Ar corresponding to the adjacent light source 2 is blocked, thereby suppressing light leakage from each area Ar corresponding to the light source 2. The incident surface side light-shielding wall 3 may have a reflective surface such as a metal coating disposed on its outer surface, or may have a highly reflective paint such as white paint applied to its outer surface. Furthermore, the incident surface side light-shielding wall 3, including its outer surface, may be formed in a state in which it is colored with a highly reflective color. Furthermore, the incident surface side light-shielding wall 3 itself may be formed from a highly reflective material, such as one with a glossy finish.

[0040] 2, the incident surface side light-shielding wall 3 includes a plate-like portion 31 and an incident surface side insertion portion 32. The plate-like portion 31 and the incident surface side insertion portion 32 are integrally formed so as to surround each of the plurality of light sources 2. The incident surface side insertion portion 32 is an example of the "portion of the incident surface side light-shielding wall on the exit surface side" in the claims.

[0041] The plate-shaped portion 31 is formed as a single plate-shaped member in which openings 31a are provided at positions corresponding to the plurality of light sources 2. The plate-shaped portion 31 is arranged so as to surround each of the plurality of light sources 2. The plate-shaped portion 31 is provided so as to partition the space 31b corresponding to each of the plurality of light sources 2.

[0042] 3, the incident surface side insertion portion 32 on the incident surface 41 side (Z1 direction side) of the incident surface side light-shielding wall 3 is arranged in a part of the interior of the diffuser plate 4 from the incident surface 41 toward the exit surface 42 side (Z1 direction side) of the diffuser plate 4. The incident surface side insertion portion 32 is a part on the incident surface 41 side of the incident surface side light-shielding wall 3. The incident surface side insertion portion 32 is inserted from the incident surface 41 of the diffuser plate 4 toward the exit surface 42 side (Z1 direction side).

[0043] The incident surface side insertion portions 32 are arranged on the light source 2 side of the diffuser plate 4 so as to surround the areas (spaces) directly above each of the plurality of light sources 2. The incident surface side insertion portions 32 have, for example, a portion extending along the X direction and a portion extending along the Y direction.

[0044] 4, the opening 31a of the plate-like portion 31 has a rectangular shape larger than the outer shape of each of the plurality of light sources 2 when viewed from the Z1 direction side. Because the opening 31a is larger than the light sources 2, the periphery of each of the plurality of light sources 2 is arranged in a state surrounded by the connection portion 52 when viewed from the Z1 direction side. The space 31b defined by the incident surface-side light-shielding wall 3 has a width of 3.0 mm, for example, when each of the plurality of light sources 2 is an LED with a width of 2 mm.

[0045] The size of the space 31b defined by the opening 31a of the plate-like portion 31 is equal to the size of the plurality of light sources 2 plus a gap for expansion and contraction and tolerance. For example, if the width of each of the plurality of light sources 2 is 2.0 mm, the distance between each of the plurality of light sources 2 and the inner surface of the opening 31a of the plate-like portion 31 is 0.5 mm, which is a gap for expansion and contraction and tolerance. In that case, the width of the space 31b defined by the opening 31a of the plate-like portion 31 in the X direction is 3.0 mm.

[0046] The light-shielding wall 3 on the incident surface side has a function of blocking light for each of the divided areas Ar and a function as a support for supporting the diffusion plate 4 .

[0047] (diffuser plate) 2, the diffusion plate 4 is a rectangular plate-like member disposed so as to face the plurality of light sources 2. The diffusion plate 4 is disposed between the plurality of light sources 2 and the light-exiting surface-side light-shielding wall 5. The diffusion plate 4 is configured to diffuse the light emitted from the plurality of light sources 2.

[0048] Specifically, the diffuser plate 4 diffuses light from the multiple light sources 2 arranged on the Z2 side and transmits the light toward the lens unit 6 arranged on the Z1 side. The diffuser plate 4 includes an incident surface 41 and an exit surface 42. The incident surface 41 is the surface on the Z2 side where light from each of the multiple light sources 2 enters. The exit surface 42 is the surface on the Z1 side where light diffused within the diffuser plate 4 exits. The diffuser plate 4 diffuses the light incident from the incident surface 41 to uniformize the brightness of the light emitted from the exit surface 42. Furthermore, if the light source 2 is configured to emit white light using a blue LED and a phosphor, color unevenness occurs between the LED chip of the light source 2 and the phosphor surrounding the LED chip. The diffuser plate 4 diffuses the light from the light source 2 internally to eliminate color unevenness. The diffuser plate 4 is formed, for example, from a resin having predetermined optical properties for diffusing the light from the light source 2.

[0049] The diffusion plate 4 will be described in detail later.

[0050] (Light-shielding wall on the exit side) 2 and 3, the light-emitting surface-side shielding wall 5 is provided to partition the area into regions Ar corresponding to the plurality of light sources 2. The light-emitting surface-side shielding wall 5 extends from the light-emitting surface 42 of the diffuser plate 4 toward the opposite side (Z1 direction side) from the plurality of light sources 2. The light-emitting surface-side shielding wall 5 is disposed so as to surround each light source 2 across a space 51b from the light-emitting surface 42 of the diffuser plate 4 to the incident surface 61 of the lens unit 6 on the diffuser plate 4 side (Z2 direction side). The light-emitting surface-side shielding wall 5 is formed, for example, from a resin.

[0051] The light-emitting surface-side shading wall 5 is configured to absorb light from the light source 2 on the outer surface of the light-emitting surface-side shading wall 5. This absorbs light, blocking light from traveling toward the space 51b corresponding to the adjacent light source 2, thereby suppressing light leakage from each space 51b corresponding to the light source 2. The outer surface of the light-emitting surface-side shading wall 5 may be coated with a highly absorbent paint such as black. Furthermore, the light-emitting surface-side shading wall 5, including its outer surface, may be formed in a state where it is colored with a highly absorbent color. Furthermore, the light-emitting surface-side shading wall 5 itself may be formed from a highly absorbent material.

[0052] The light-emitting surface-side shading wall 5 is configured to absorb light from the light source 2 on its outer surface. This absorbs light, blocking light from traveling toward the spaces 51b corresponding to the adjacent light sources 2, thereby suppressing light leakage from each space 51b corresponding to the light source 2. The light-emitting surface-side shading wall 5 may have its outer surface coated with a highly light-absorbing paint, such as black paint (e.g., acrylic paint). The light-emitting surface-side shading wall 5, including its outer surface, may be colored with a highly light-absorbing color. The light-emitting surface-side shading wall 5 itself may be made of a highly light-absorbing resin (e.g., ABS resin (acrylonitrile butadiene styrene resin), PC resin (polycarbonate resin)), a surface-treated metal (aluminum, iron), paper, or the like.

[0053] 3, the light-emitting surface-side shielding wall 5 includes a wall portion 51, a connection portion 52, and a light-emitting surface-side insertion portion 53. The wall portion 51, the connection portion 52, and the light-emitting surface-side insertion portion 53 are integrally formed so as to surround each of the plurality of light sources 2.

[0054] The wall portion 51 is formed as a plate-shaped frame member so as to separate the areas Ar corresponding to each of the plurality of light sources 2 (see FIG. 4). That is, the wall portion 51 is disposed between the areas Ar of adjacent light sources 2. In this manner, the wall portion 51 of the frame member has spaces 51b at positions corresponding to each of the plurality of light sources 2. As a result, light from each of the plurality of light sources 2 is incident on the lens unit 6 for each corresponding area Ar via the spaces 51b. The wall portion 51 of the frame member protrudes in the Z1 direction from the Z1-direction side surface of the connection portion 52. The wall portion 51 is provided so as to separate the areas Ar corresponding to each of the plurality of light sources 2. The end of the wall portion 51 on the Z1 direction side has a base portion 51a on which the lens unit 6 is placed. The base portion 51a has a flat surface along the XY plane.

[0055] The light-shielding wall 5 on the light-emitting surface side has a function of blocking light for each of the partitioned areas Ar and a function as a support for supporting the lens portion 6.

[0056] The connecting portion 52 is a portion that connects the wall portion 51 of the frame member and the light-emitting surface-side insertion portion 53. The connecting portion 52 extends along the light-emitting surface 42 of the diffuser plate 4. In addition, the connecting portion 52 has openings 52a formed at positions corresponding to the plurality of light sources 2, respectively.

[0057] 4, the opening 52a has a rectangular shape that is smaller than the outer shape of each of the plurality of light sources 2 when viewed from the Z1 direction side. Because the opening 52a is smaller than the light sources 2, the peripheral edge of each of the plurality of light sources 2 is arranged in a state covered by the connection portion 52 when viewed from the Z1 direction side. For example, if each of the plurality of light sources 2 is an LED with a width of 2 mm, the width W1 of the opening 52a is 1.9 mm, which is smaller than the width of each of the plurality of light sources 2. The width W2 in the X direction of the space 51b partitioned by the wall portion 51 is larger than the width W1 of the opening 52a.

[0058] As shown in FIG. 3, the exit surface side insertion portion 53 on the incident surface 41 side (Z2 direction side) of the exit surface side light-shielding wall 5 is arranged in a part of the interior of the diffuser 4 from the exit surface 42 of the diffuser 4 toward the incident surface 41 side (Z2 direction side). The exit surface side insertion portion 53 is a portion on the incident surface 41 side of the exit surface side light-shielding wall 5. The exit surface side insertion portion 53 is inserted from the exit surface 42 of the diffuser 4 toward the incident surface 41 side (Z2 direction side). The exit surface side insertion portion 53 is inserted from the exit surface 42 of the diffuser 4 toward the incident surface 41 side (Z2 direction side) to a depth of 50% or more of the thickness of the diffuser 4.

[0059] The exit surface side insertion portions 53 protrude in the Z2 direction from the end surface of the connection portion 52 on the exit surface 42 side. A pair of exit surface side insertion portions 53 is provided on each end of the end surface of the connection portion 52 on the exit surface 42 side, in the X and Y directions. When viewed from the Z1 direction, the incident surface side insertion portion 32 is disposed between the pair of exit surface side insertion portions 53. The exit surface side insertion portions 53 are disposed on the light source 2 side of the diffuser 4 so as to surround the area directly above each of the plurality of light sources 2. The exit surface side insertion portions 53 are disposed independently for each area Ar defined by surrounding the area defined for each light source 2. In other words, the exit surface side insertion portions 53 are disposed from the exit surface 42 in the Z2 direction so as to surround the area overlapping with the light source 2. The exit surface side insertion portions 53 have, for example, a portion extending along the X direction and a portion extending along the Y direction. The light exit surface side insertion portion 53 is formed in a lattice pattern.

[0060] Furthermore, the light exit surface side insertion portion 53 arranged inside the diffuser plate 4 defines an area smaller than the area defined by the wall portion 51 at a position directly above each of the plurality of light sources 2 on the Z1 direction side.

[0061] (Meandering section) 5, the diffuser plate 4 of this embodiment has a serpentine portion 43. The serpentine portion 43 is a portion of the diffuser plate 4 that is provided so as to bend back in both the direction from the incident surface 41 toward the exit surface 42 (Z1 direction) and the direction from the exit surface 42 toward the incident surface 41 (Z2 direction). The serpentine portion 43 causes the incident light to meander.

[0062] 6, the serpentine-shaped portion 43 is configured to meander the optical path of the propagating light Li so that the light Li propagating through the diffuser 4 does not leak into the opening 52a of the region Ar corresponding to the adjacent light source 2. The serpentine-shaped portion 43 is provided along the incident surface 41 and the exit surface 42 of the diffuser 4, and is provided to meander the optical path toward the adjacent region Ar. The serpentine-shaped portion 43 does not reduce the amount of light transmitted toward the opening 52a facing the light source 2. The serpentine-shaped portion 43 is formed at the boundary between the regions Ar corresponding to multiple light sources 2.

[0063] Note that the serpentine-shaped portion 43 may have a protrusion that protrudes toward the opening 52a (protrudes in the Z1 direction) in the meandering optical path. This increases the optical path length of the serpentine-shaped portion 43 by the amount of the protrusion. Furthermore, by providing a protrusion that protrudes toward the opening 52a, leaked light can be guided into the protrusion, allowing more leaked light to be captured. This further reduces light leaking into the opening 52a in the adjacent region Ar.

[0064] 5 and 6, serpentine portion 43 is a portion of diffuser plate 4 in which incident surface groove portion 41a and exit surface groove portion 42b are formed. Incidentally, incident surface groove portion 41a and exit surface groove portion 42b are each an example of the "plurality of grooves" in the claims.

[0065] The incident surface groove 41a has a convex shape extending from the incident surface 41 toward the exit surface 42 (in the Z1 direction). The incident surface insertion portion 32 is inserted into the incident surface groove 41a. A plurality of incident surface grooves 41a are arranged in accordance with the positions of the incident surface insertion portions 32. Each of the plurality of incident surface grooves 41a has, for example, a portion extending along the X direction and a portion extending along the Y direction. The plurality of incident surface grooves 41a are formed in a lattice pattern. Each of the plurality of incident surface grooves 41a has a depth corresponding to the height of the incident surface insertion portion 53.

[0066] The exit surface groove 42b has a concave shape extending from the exit surface 42 toward the entrance surface 41 (in the Z2 direction). The exit surface insertion portion 53 is inserted into the exit surface groove 42b. A plurality of the exit surface grooves 42b are arranged in accordance with the positions of the exit surface insertion portions 53. The plurality of the exit surface grooves 42b have, for example, a portion extending along the X direction and a portion extending along the Y direction. The plurality of the exit surface grooves 42b are formed in a lattice pattern. The plurality of the exit surface grooves 42b have a depth that matches the height of the exit surface insertion portions 53.

[0067] Incident surface grooves 41a and exit surface grooves 42b are arranged so as to be offset in both the X and Y directions. The multiple incident surface grooves 41a are arranged so as to be offset from one another by a predetermined distance in a direction perpendicular to the Z direction. The multiple exit surface grooves 42b are arranged so as to be offset from one another by a predetermined distance in a direction perpendicular to the Z direction.

[0068] The meandering portion 43 causes the optical path to meander, increasing the number of times that the light Li is reflected and diffused within the diffuser plate 4 before propagating to the adjacent region Ar, thereby reducing the leakage of the light Li. Furthermore, the meandering optical path length increases the number of times that the light Li is reflected and diffused, further reducing the amount (energy) of the light Li and reducing the leakage of the light Li into the openings 52a of the adjacent region Ar. Furthermore, the inserted incident surface insertion portion 32 reflects the light Li emitted from the incident surface groove 41a of the meandering portion 43 back to the meandering portion 43, and the reflected and returned light Li is reflected and diffused by the meandering portion 43. This reduces the amount (energy) of the reflected and returned light Li, reducing the leakage of the light Li. Furthermore, the light Li emitted from the light exit surface groove 42b of the serpentine-shaped portion 43 is absorbed by the inserted light exit surface insertion portion 53, thereby reducing leakage of the light Li. As a result, the light Li propagating to the region Ar corresponding to the adjacent light source 2 by the serpentine-shaped portion 43 is blocked.

[0069] (Lens part) As shown in FIG. 3, the lens unit 6 is disposed on the opposite side (Z1 direction side) of the diffuser plate 4 from the plurality of light sources 2. The lens unit 6 refracts light emitted from each of the plurality of light sources 2 into parallel light for each area Ar defined by the light-emitting surface-side shielding wall 5. Specifically, the lens unit 6 refracts light incident on the area Ar defined by the light-emitting surface-side shielding wall 5 via the diffuser plate 4 into parallel light traveling in the Z1 direction. The lens unit 6 is disposed so as to have a focal point Pf (see FIG. 4) for each of the plurality of light sources 2. That is, the lens unit 6 is a plate-shaped member formed by combining a plurality of convex lenses, each of which is disposed for each light source 2. In the lens unit 6, the focal point Pf of the convex lens disposed for each light source 2 is disposed so as to be the center of the opening 52a in the XY plane.

[0070] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0071] In this embodiment, as described above, the backlight 40 includes the incident surface-side light-shielding wall 3 and the exit surface-side light-shielding wall 5. The incident surface-side light-shielding wall 3 can thereby suppress leakage of light from each of the multiple light sources 2 into adjacent spaces 31b between the substrate 1 and the incident surface 41 of the diffuser 4. The exit surface-side light-shielding wall 5 can also suppress leakage of light from each of the multiple light sources 2 into adjacent regions Ar in the space 51b on the opposite side of the exit surface 42 of the diffuser 4 from the multiple light sources 2. These features can suppress light leakage not only in the space 31b between the substrate 1 and the incident surface 41 of the diffuser 4, but also in the space 51b on the opposite side of the exit surface 42 of the diffuser 4 from the multiple light sources 2. Furthermore, suppressing leakage of light Li can suppress light from the display panel 20 from emitting at an unintended viewing angle in the regions Ar of each of the multiple light sources 2.

[0072] Furthermore, in this embodiment, as described above, the exit surface-side light-shielding wall 5 includes the exit surface-side insertion portion 53 that is inserted from the exit surface 42 of the diffuser plate 4 toward the incident surface 41. This allows the exit surface-side insertion portion 53 to block (absorb or reflect) light that propagates through the diffuser plate 4 toward the region Ar where the other light source 2 is arranged, and that has transmitted up to the exit surface 42 side of the diffuser plate 4. This makes it possible to prevent light from one of the adjacent light sources 2 from leaking into the region Ar where the other light source 2 is arranged. As a result, it is possible to prevent light from being emitted from the display panel 20 at an unintended viewing angle due to leaked light (unwanted light) from one of the light sources 2.

[0073] Furthermore, in this embodiment, as described above, the diffuser plate 4 includes the exit surface grooves 42a (exit surface grooves 42b) into which the exit surface insertion portions 53 are inserted and which are recessed from the exit surface 42 toward the incident surface 41. Thus, by inserting the exit surface insertion portions 53 into the exit surface grooves 42a (exit surface grooves 42b), the light emitted from the exit surface grooves 42a (exit surface grooves 42b) can be blocked by the exit surface insertion portions 53, thereby further preventing light from one adjacent light source 2 from leaking into the area Ar where the other light source 2 is arranged.

[0074] Furthermore, in this embodiment, as described above, the incident surface-side light-shielding wall 3 includes the incident surface-side insertion portion 32 that is inserted from the incident surface 41 of the diffuser plate 4 toward the exit surface 42. This allows the incident surface-side insertion portion 32 to block (absorb or reflect) the light on the incident surface 41 side of the diffuser plate 4 that propagates through the diffuser plate 4 toward the area Ar where the other light source 2 is arranged. This makes it possible to prevent light from one of the adjacent light sources 2 from leaking into the area Ar where the other light source 2 is arranged. As a result, it is possible to prevent light from being emitted from the display panel 20 at an unintended viewing angle due to leaked light (unwanted light) from one of the light sources 2.

[0075] Furthermore, in this embodiment, as described above, the diffuser plate 4 includes incident surface grooves 41a into which the incident surface insertion portions 32 are inserted and which are recessed from the incident surface 41 toward the exit surface 42. This allows the incident surface insertion portions 32 to be inserted into the incident surface grooves 41a, so that the light emitted from the incident surface grooves 41a can be easily blocked by the incident surface insertion portions 32, thereby further preventing the light from one adjacent light source 2 from leaking into the area Ar where the other light source 2 is arranged.

[0076] Furthermore, in this embodiment, as described above, the portion of the incident surface-side light-shielding wall 3 on the exit surface 42 side is arranged in a part of the interior of the diffuser 4 from the incident surface 41 of the diffuser 4 toward the exit surface 42 side. The portion of the exit surface-side light-shielding wall 5 on the incident surface 41 side is arranged in a part of the interior of the diffuser 4 from the exit surface 42 of the diffuser 4 toward the incident surface 41 side. As a result, with respect to light that propagates through the diffuser 4 toward the region Ar where the other light source 2 is arranged, the part of the incident surface-side light-shielding wall 3 arranged in a part of the interior of the diffuser 4 can block (absorb or reflect) the light on the incident surface 41 side of the diffuser 4, and the part of the exit surface-side light-shielding wall 5 arranged in a part of the interior of the diffuser 4 can block (absorb or reflect) the light on the exit surface 42 side of the diffuser 4. This effectively prevents light from one of the adjacent light sources 2 from propagating through the diffuser 4 and leaking into the region Ar where the other light source 2 is arranged.

[0077] In the present embodiment, as described above, the diffuser 4 has a portion of the incident surface-side light-shielding wall 3 on the exit surface 42 side and a portion of the exit surface-side light-shielding wall 5 on the incident surface 41 side each disposed inside the diffuser 4, and includes a plurality of grooves (incident surface-side grooves 41a and exit surface-side grooves 42a) that are shifted in a direction perpendicular to the direction from the incident surface 41 toward the exit surface 42. The diffuser 4 is provided so as to bend back in each of the direction from the incident surface 41 toward the exit surface 42 (Z1 direction) and the direction from the exit surface 42 toward the incident surface 41 (Z2 direction) by the plurality of grooves, and includes serpentine-shaped portions 43 along the incident surface 41 and the exit surface 42 of the diffuser 4. As a result, the light Li from one light source 2 does not propagate through the diffuser plate 4 in a direction parallel to the direction from one light source 2 to the other light source 2, but the direction of propagation of the light Li changes in various directions due to the serpentine-shaped portion 43, making it difficult for the light Li from one light source 2 to propagate through the diffuser plate 4 and reach the area Ar where the other light source 2 is arranged. Furthermore, by providing the serpentine-shaped portion 43, the optical path length of the light Li propagating through the diffuser plate 4 in the direction from one light source 2 to the other light source 2 can be extended, thereby increasing the number of reflections and diffusions of the propagating light Li. This reduces the amount of propagating light Li, further suppressing light leakage into the adjacent area Ar of the other light source 2 adjacent to one light source 2.

[0078] Furthermore, in this embodiment, as described above, the backlight 40 includes the exit surface-side light-shielding wall 5 and the incident surface-side light-shielding wall 3. This makes it possible to suppress light leakage not only in the space 31b between the substrate 1 and the incident surface 41 of the diffuser plate 4, but also in the space 51b on the opposite side of the multiple light sources 2 from the exit surface 42 of the diffuser plate 4. Furthermore, by suppressing light leakage, it is possible to easily control the brightness of light emitted from the exit surface 42 of the diffuser plate 4 in each region Ar of the multiple light sources 2 individually. Furthermore, with respect to light propagating through the diffuser plate 4 toward the region Ar where the other light source 2 is located, the portion of the entrance surface-side light-shielding wall 3 located in a part of the interior of the diffuser plate 4 can block (absorb or reflect) the light on the entrance surface 41 side of the diffuser plate 4, and the portion of the exit surface-side light-shielding wall 5 located in a part of the interior of the diffuser plate 4 can block (absorb or reflect) the light on the exit surface 42 side of the diffuser plate 4. This makes it possible to effectively prevent light from one of the adjacent light sources 2 from propagating through the diffusion plate 4 and leaking into the area Ar where the other light source 2 is arranged.

[0079] Furthermore, in this embodiment, as described above, the display device 100 includes the incident surface-side light-shielding wall 3 and the exit surface-side light-shielding wall 5. This makes it possible to provide the display device 100 that can suppress light leakage not only in the area Ar between the substrate 1 and the incident surface 41 of the diffuser plate 4 but also in the area Ar on the opposite side of the exit surface 42 of the diffuser plate 4 from the multiple light sources 2.

[0080] [Variations] The present invention is not limited to the above embodiments, but is illustrated by the claims, and includes all modifications within the scope of the claims.

[0081] For example, in the above embodiment, an example was shown in which the incident surface side insertion portion 32 is arranged between the pair of incident surface side insertion portions 53 when viewed from the Z1 direction side, but the present invention is not limited to this. In the present invention, as in the modified example shown in Fig. 7, the incident surface side insertion portion 253 may be arranged between the pair of incident surface side insertion portions 232 when viewed from the Z1 direction side.

[0082] Furthermore, in the above embodiment, an example was shown in which the incident surface side light-shielding wall 3 includes the incident surface side insertion portion 32 and the exit surface side light-shielding wall 5 includes the exit surface side insertion portion 53, but the present invention is not limited to this. In the present invention, the incident surface side light-shielding wall may not include the incident surface side insertion portion, and the exit surface side light-shielding wall may not include the exit surface side insertion portion. Furthermore, the incident surface side light-shielding wall may include the incident surface side insertion portion, and the exit surface side light-shielding wall may not include the exit surface side insertion portion, or the incident surface side light-shielding wall may not include the incident surface side insertion portion, and the exit surface side light-shielding wall may include the exit surface side insertion portion.

[0083] In the above embodiment, the diffusion plate 4 includes the serpentine portion 43, but the present invention is not limited to this. In the present invention, the diffusion plate does not necessarily have to include the serpentine portion. Furthermore, the diffusion plate may include a labyrinth-shaped portion instead of the serpentine portion.

[0084] In the above embodiment, the diffuser plate 4 has the groove-shaped incident surface grooves 41a formed therein, but the present invention is not limited to this. In the present invention, the diffuser plate may have the incident surface recesses formed therein instead of the groove-shaped recesses.

[0085] In the above embodiment, the diffuser plate 4 has the groove-shaped exit surface grooves 41b formed therein, but the present invention is not limited to this. In the present invention, the diffuser plate may have the exit surface recesses formed therein instead of the groove-shaped recesses.

[0086] Furthermore, in the above embodiment, an example was shown in which the lens unit 6 was provided to refract the light emitted from each of the multiple light sources 2 into parallel light, but the present invention is not limited to this. In the present invention, the lens unit may not be provided. Furthermore, if a lens unit is provided, a diffusion plate that diffuses the light emitted from the lens unit may also be provided.

[0087] In the above embodiment, the opening 52a of the light-emitting surface-side shielding wall 5 has a shape smaller than the outer shape of each of the plurality of light sources 2, but the present invention is not limited to this. In the present invention, the opening of the light-emitting surface-side shielding wall may be the same size as or larger than the outer shape of each of the plurality of light sources. Furthermore, the shape of the opening may be different from the shape of the light source. For example, the shape of the opening may be circular.

[0088] In the above embodiment, the backlight 40 is disposed in the display device 100, which is a liquid crystal television device, but the present invention is not limited to this. In the present invention, the display device may be a monitor display or the like different from a television device.

[0089] In the above embodiment, the light-emitting surface-side light-shielding wall 5 partitions the diffuser plate 4 into regions Ar corresponding to the plurality of light sources 2, each region Ar corresponding to one of the plurality of light sources 2 arranged in a lattice pattern. However, the present invention is not limited to this. In the present invention, the regions Ar corresponding to the plurality of light sources may be partitioned into regions Ar for two or more light sources. The plurality of light sources may also be arranged in a honeycomb structure. In this case, the shape of the regions Ar partitioned by the partitioning members may also be arranged in a honeycomb structure so as to correspond to the plurality of light sources. [Explanation of symbols]

[0090] 2 light source 3 Light-shielding wall on the incident surface side 4 Diffuser 5. Light-shielding wall on the exit side 20 Display panel 32, 232 Insertion part on the incident surface side 40 Backlight (light source device) 41 Entrance plane 41a Incident surface groove 42 Exit surface 42a Exit surface groove 42b Exit surface groove 43 Serpentine section 53, 253 Insertion part on the exit surface 61 Entrance plane 100 display device Ar region Li-light

Claims

1. Multiple light sources; a diffusion plate that is disposed to face the plurality of light sources and that diffuses light emitted from the plurality of light sources; an incident surface-side light-shielding wall that surrounds each of the plurality of light sources and is provided to partition the area into regions corresponding to each of the plurality of light sources, and that extends from the plurality of light sources toward a light incident surface side of the diffuser plate; a light source device comprising: an exit surface side light shielding wall that is arranged to divide the area into regions corresponding to each of the plurality of light sources and that extends from the light exit surface of the diffusion plate toward the opposite side to the plurality of light sources.

2. The light source device according to claim 1 , wherein the light-emitting surface side light-shielding wall includes an emission surface side insertion portion that is inserted from the emission surface of the diffusion plate toward the incident surface side.

3. The light source device according to claim 2 , wherein the diffusion plate includes an exit surface groove portion into which the exit surface insertion portion is inserted and which is recessed from the exit surface toward the incident surface side.

4. The light source device according to claim 1 , wherein the incident surface side light-shielding wall includes an incident surface side insertion portion that is inserted from the incident surface of the diffusion plate toward the exit surface side.

5. The light source device according to claim 4 , wherein the diffusion plate includes an incident surface groove portion into which the incident surface insertion portion is inserted and which is recessed from the incident surface toward the exit surface side.

6. a portion of the incident surface-side light-shielding wall on the exit surface side is disposed in a part of the interior of the diffuser plate from the incident surface of the diffuser plate toward the exit surface side, The light source device according to claim 1 , wherein the portion of the light-emitting surface-side shielding wall on the incident surface side is disposed in a part of the interior of the diffuser plate from the light-emitting surface of the diffuser plate toward the incident surface side.

7. The diffusion plate is a plurality of grooves disposed inside the diffuser plate, each of which is disposed in a portion of the incident surface side light-shielding wall on the side of the exit surface and a portion of the incident surface side light-shielding wall on the side of the exit surface, the grooves being shifted in a direction perpendicular to a direction from the incident surface toward the exit surface; 7. The light source device of claim 6, wherein the plurality of grooves are arranged to fold back in each of the directions from the incident surface toward the exit surface and from the exit surface toward the incident surface, and the light source device further includes a serpentine-shaped portion along the incident surface and the exit surface of the diffuser plate.

8. Multiple light sources; a diffusion plate that is disposed to face the plurality of light sources and that diffuses light emitted from the plurality of light sources; an exit surface side light-shielding wall disposed on the opposite side of the diffusion plate from the plurality of light sources, the light-shielding wall dividing the diffusion plate into regions corresponding to the plurality of light sources; an incident surface side light-shielding wall that is disposed on the diffuser plate on a side of the plurality of light sources and surrounds the plurality of light sources in regions corresponding to the plurality of light sources, the light-exiting surface-side light-shielding wall is disposed inside the diffuser plate from an outer surface of the diffuser plate opposite to the plurality of light sources toward the plurality of light sources, The light source device, wherein the incident surface side light-shielding wall is disposed inside the diffuser plate from the outer surface of the diffuser plate on the side of the plurality of light sources toward an opposite side to the side of the plurality of light sources.

9. Multiple light sources; a diffusion plate that is disposed to face the plurality of light sources and that diffuses light emitted from the plurality of light sources; a display panel disposed on the opposite side of the diffusion plate from the plurality of light sources; an incident surface-side light-shielding wall that surrounds each of the plurality of light sources and is provided to partition the area into regions corresponding to each of the plurality of light sources, and that extends from the plurality of light sources toward a light incident surface side of the diffuser plate; a light exit surface-side shading wall that is arranged to divide the display into areas corresponding to the plurality of light sources and that extends from the light exit surface of the diffusion plate toward the opposite side to the plurality of light sources.

Images